Natetrue has posted information regarding the 1.1.3 firmware workings, and it looks like 1.1.3 is ready for SDK apps.

The main points he lists are:

• Application data is now stored in /var/mobile instead of /var/root
• Applications are now running as user mobile, not root
• SpringBoard no longer requires SummberBoard for scrolling pages

In other words, 1.1.3 is already for SDK apps to be installed, although the SDK is not out yet, nor are SDK apps.

cre.ations.net